It's available for extensions I think (there's also the higher-level WebGL which you must be aware of), and requires whitelisted graphic drivers. As you can see

It's available for extensions I think (there's also the higher-level WebGL which you must be aware of), and requires whitelisted graphic drivers. As you can see, graphic acceleration offers a huge attack surface (memory-unsafety in C++ code, plus logic bugs at highly privileged levels like graphic drivers, firmware, and the hardware itself). Some of these layers realistically won't be protected until they have proper IOMMU support.